Ryan Howard sat out Sunday’s game with a sore left knee and the Phillies first baseman is getting an MRI exam today.

Howard told Stephen Pianovich of MLB.com that the knee “has been acting up a little bit since spring training” but “yesterday was when it really kind of kicked in more than normal.”

Howard has been in the starting lineup for 39 of the Phillies’ first 44 games, but he’s hitting just .242 with a career-worst .713 OPS and terrible 46/9 K/BB ratio. And dating back to last season Howard has a .229 batting average and .716 OPS in his last 112 games after previously never posting a sub-.835 OPS in a season.

At age 33 he’s showing major signs of decline, but Howard is making $20 million this season and the Phillies still owe him another $85 million for 2014-2016.